Explanations and comparisons
Reminders
- Workbook homework due on Thursday
Goals
Begin looking at relationships between variables
Theoretical Arguments and Hypotheses
Elements of a good theory
Writing good hypotheses
Testing Hypotheses
The goals of research
Describing: making generalization about the world
Predicting: generating expectations about what will happen in the future
Explaining: explaining why things are related.
Explanation is often the toughest to achieve, but also the most desirable because it allows us to do things like make changes to reach a desired outcome.
“Why” questions
“Why questions”
- Why do some eligible voters fail to turn out on election day?
- What explains variation in gun policies across U.S. states?
- Why did communist revolutions happen in China and Russia but not Europe or the United States?
Theories
“a logically interconnected set of propositions from which empirical uniformities can be derived” – Robert K Merton
Theories are explanations, assumptions, claims and narratives that provide a set of expectations that link a cause to an effect.
Purely descriptive or predictive analyses don’t necessarily require a theory, but its a key component of explanatory research.
Assessing Theories
Theories require simplified representations of a complex reality
Utility, not “truth”: theoretical models invariably contain assumptions and they’re probably violated in practice.
Theoretical Scope
Theories vary in their scope:
- Early sociologists like Marx, Durkheim, Weber attempted to develop all-encompassing “laws” of political/social/historical change. These are sometimes called “grand theories”
- Contemporary social sciences are less ambitious, and so its more common to propose “middle-range” theories that seek to explain a smaller number regularities in one area.
- However, they may draw on “grand theories” either implicitly or explicitly.
Grand theories: Paths to Modernity
What explains differences in the “path to modernity” across different countries during the 20th century?
Free markets/Democracy in the U.S. and England
Fascism in Germany and Japan
Communism in Russia and China
Grand theories: Paths to Modernity
Barrington Moore: Classes have unique and conflicting interests. Conflicts over these interests come to the forefront during industrialization. The outcomes of these class conflicts shape the political and economic system.
Grand theories: Paths to Modernity
Fascist states emerge when the landed aristocracy allies with industry to repress the peasantry.
Communist states emerge when the middle class doesn’t emerge and peasants revolt.
Democracies emerge when the bourgeoisie (middle class) is strong.
Grand theories: Paths to Modernity
Moore’s theory borrows assumptions from a (sociological) Marxist grand theory about class conflict
He “tests” it by showing how it fits the selected cases.
Grand theories: Paths to Modernity
Good theories can be used and refined to generate a set of empirical expectations about what factors should matter. For instance, we might expect:
States with larger agricultural sectors during industrialization to be less democratic today (compared to states with smaller agricultural sectors)
States with higher literacy rates during industrialization to be more democratic (compared to states with lower literacy rates)
Good Theories
Good theories clearly identify:
A dependent variable(s): the outcome to be explained
One or more independent variables: the causal factors that determine the DV.
A causal mechanism that links these two things.
An expectation about the direction of the effect (positive, negative, something more complex)
Good theories
Most social science theories are probabilistic instead of deterministic. So we’ll speak in terms of more/less likely or higher/lower.
Good theories should generate expectations that can be empirically tested (even if the theory itself can’t be tested)
Causal diagrams
- Causal diagrams are a way to visualize cause and effect relationships in a theoretical model.
Causal diagrams
- Nodes indicate variables, and arrows indicate causal relationships.
Causal diagrams
For instance, we might think about a simplified version of Moore’s thesis like this
Causal diagrams: forks
A “fork” refers to a case where a single cause leads to multiple outcomes of interest.
Causal diagrams: collisions
A “collision” happens when two causes “collide” on a single outcome:
Causal diagrams: chains
A chain refers to a scenario where one outcome causes something else, which influences a third thing.
Causal diagrams
- In practice, causal diagrams will usually be a lot more complicated than this, but the end goal is systematically identify testable claims about some outcome.
Theories: voting
Why do people vote?
Since politicians generally offer public goods, you can enjoy the benefits of your preferred candidate winning even if you don’t vote
Since voting has costs (even though they’re small) free riding can be preferable to actually turning out if the costs outweigh the benefits.
Theories: voting
Pivotal voting
Claim: people vote because they expect to sway the election
If this is true, then:
- Turnout should be higher in close elections
- Turnout should be higher when the electorate is small
- Turnout will be higher in PR systems where one vote matters more.
Theories: voting
Expressive voting model
Claim: people vote to enjoy the expressive benefits
If this is true then:
- People with more extreme beliefs will be more likely to vote
- Closeness or the size of the electorate shouldn’t matter much
Assessing Theories
Consistency
- Is our theory internally consistent?
- Does it have a clear logic?
Assessing Theories
Empirical accuracy
- Do the theories help us understand the world?
- Are observed realities consistent with the expectations our theory generates?
- Can we use a theory to make useful predictions about future events?
- Can the theory adapt in the face of inconsistent findings? (this will happen!)
Hypotheses
Theories give causal explanations for why something effects something else
Hypotheses are specific testable implications generated by that theory.
Theory: people vote because of expressive benefits
Hypothesis: people with more extreme views will be more likely to turn out.
Hypotheses
Components:
Unit of analysis
Dependent variable
Independent variable
Direction of the predicted relationship
Good hypotheses inevitably involve comparative language (higher/lower/more/less/increase/decrease/better/worse)
Hypothesis Template
In a comparison of [unit of analysis], those having [one value on the independent variable] will be [more/less] likely to have [one value on the dependent variable] than those having a [different value on the independent variable].
Hypothesis Template
In a comparison of [voters], those having [stronger political views] will be more likely to have [a higher likelihood of turnout] than those having a [weaker views].
Unit of analysis: voters
IV: strength of political views
DV: turnout
Relationship: strength increases turnout
Hypothesis Template
In a comparison of [states], those having [a larger middle class during industrialization] will be more likely to have [democracy] than those having a [a smaller middle class].
Unit of analysis: states
IV: size of the middle class
DV: democracy
Relationship: middle class increases likelihood of democracy
Hypothesis Template
In a comparison of [survey respondents], those having [higher levels of attention to politics] will be more likely to have [consistent responses] than those having a [lower levels of attention to politics].
Unit of analysis: Survey respondents
IV: level of attention
DV: response consistency
Relationship: attention increases consistency
Complex Relationships
Good hypotheses may suggest a more complex set of relationships than just “positive/negative”. They could propose conditional/interactive/curvilinear relationships as well.
The “oil curse”
In a comparison of [countries], those having [higher levels of GDP] will be [more likely to be democratic] compared to [countries with lower GDP], [however, this relationship will not hold for countries that get rich from oil exports.]
Retrospective voting:
In a comparison of [voters], those having [lower levels of attention to politics] will be [more likely to vote for the incumbent when the economy is doing well]. Those having [higher levels of attention to politics] will be [more likely to vote based on policy preferences regardless of the state of the economy]
Bad hypotheses
The main determinant of war is the distribution of power in the international system.
In comparing individuals, annual income and the level of education are related.
Democracies are peaceful. In comparing individuals, some people are more likely to favor the death penalty than others.
Next
Testing hypotheses by making comparisons
Graphing and describing relationships
George Box: “All models are wrong, but some are useful”
From Vincent Arel-Bundock